With the development of science and technology, new products and technologies are constantly innovating. LEDs as new light sources have the characteristics of energy saving, environment-friendly and high efficiency. The LED technology has matured and is applied to various fields. Therefore, LEDs are widely used. In order to ensure that the LED load can be driven by the mains electricity, the industry produces LED products with an operating voltage in the peak voltage of the mains electricity, that is, in the range of 1.414 times the effective value of the mains electricity. Since the electric power is equal to the current multiplied by the voltage (W=V*I), if the voltage is limited and the luminous efficiency of the LED load is to be increased, only the amount of the LED load can be increased, or the current passing through the LED load can be increased. However, increasing the amount of LED load will increase the cost, and the increase in current will increase the heat generated by the LED load greatly, and the operating temperature is also increased greatly. Therefore, the service life of the LED load is shortened.